Commutator



C H. WALKER.

OMMUTATOR. APPL N nuzn'ocr'. 30. 1919.

Patented Apr. 26, 1921.

UNITED STATES CLARENCE H. WALKER, 0F LARCHMONT, NEW YORK.

oommu'rnron.

To all whom it may concern: Be it known that I, CLARENCE H. WALKER, a citizen of the United States, and a resident of Larchmont, county of Westchester, and State of New York, have invented certain new and useful Improvements in Com mutators, of which the following is a specification.

My invention relates to commutators, such as timers, distributers and the like, for the ignition current of internal combustion momembers are formed in molding the matetors.

For the purposes of affording an understanding of my invention I illustrate and describe same hereinin connection with its use as a timer for the ,Ford automobile engine.

The present engine is more especially concerned with the improvement of the shell carrying the relatively stationary contact members, which shell is adjustableto advance or retard the spark in well known manner. A rotating element serves to carry the ignition current in succession to the various members contained in such shell.

According to present invention, such shell member is made of refractory material, such as porcelain, and the openings to receive the contact members are formed therein and the contact members are separately secured in. such openings in the completed shell, as by being bolted in place therein. The openings for the contact members are preferably formed in molding, or casting, or otherwise forming the shell of refractory material.

My improved shell can be readily and cheaply constructed, and none of, the difliculties are encountered which occur, for example, with the insertion of metallic inserts in making shells of molded material, such as bakelite, condensite or the like. The shell of refractory material is its own insulator,

- and metallic inserts can be secured, therein directly and without the provision of any separate insulating members, such were required, for example, when a metallic shell is made use of, requiring separate insulating.

ieces of fiber or the like materials.

With the foregoing and related objects in view, my invention consists in the features of construction and combinations herein set forth and claimed,

In the drawing forming a part of the specification, Figure 1 is a top view of a Specification of Letters Patent.

Patented Apr. 26, 1921.

Application filed October 30, 1919. Serial No. 834,424.

' cally insulating material, such, for example,

as porcelain. When constructed of porcelain, which is a good embodiment of the invention, the openings for the contact rial. In the form shown such openings, which are indicated generally by the reference numeral 11, are provided with top and bottom recesses 12 and 13, serving respectively, for the reception of the head 14 of the contact member 15 and the washer '16 of yielding material, such as fiber or the like, which is preferably placed under the nut 17 in securing the contact member 15 in place in the commutator. The binding nut 18 may serve also thefunction of a lock nut for assisting in the holdingfunction of nut 17. The two nut arrangement shown is preferable for cheapness and simplicity, but the contact members may be fastened into the shell after the same has been completed,

in various other ways. In the form shown there are four contact members 15, but the number thereof corresponds to the number of engine cylinders served by the commutator, as will be understood. The operating lever 19 for the commutator is made integral with the shell 10 and is provided with the customary opening 20 for the actuating device, such as a link or other connecting part, which serves to turn the shell 10 to advance or retard the spark.

' The rotating member may-be of various forms. In the form shown the rotary shaft 21, which in the Ford automobile engine is the cam shaft, has a sleeve 22 fast thereon, and having a link 28 pivoted thereto. Contact point 25 is carried on link 23 and spring 24 acts to press said point against the interior race 26, which forms an integral part of shell 10, and point 25 makes contact, as it is rotated, with the heads 14 of the contact members 15, thereby insuring the proper distribution of the electrical current for ignition purposes. The spring member 27 provided'with the knob or point 28, entering the. central recess or depression 29 in the top of the shell 10 serves to hold the same in place on its seat and also serves, to some extent, as an outer bearing therefor, as in the customary Ford practice.

lVhile it is the preferable construction to form the openings 11 for the contact'members 15 with their axes extending substan tially parallel to theaXis of rotation ofthe operating shaft, the same may be arranged in different relations, as for example, the contact members may be placed inthe lateral flange of the shell 10, in which case,

of course, the rotating member of the commutator will be constructed to cooperate therewith, as, for example, in the ordinary manner now in common usein thetimer of the Ford automobile engine.

Commutators in accordance with my invention have numerous advantageous features. The shell is simply and cheaply constructed; is sufficiently strong and 1 durable for the purposes for which it'is intended; difficulties of molding the shell with metallic contact members in place therein are avoided, and-theshell itself acts as its own insulating device.

The hardness andcapacity ofthe porcelain to resist wear is'substantiallyequivalent to the'ha'rdness and wear resisting capacity of steel, so that the shell, instead of being grooved out by wear in use, and the contact surfaces projecting to form raised places or bumps, as in the case of shells use. In my claim I-refer to a shell of ready made of fiber, bakelite and other insulating materials, remains smooth and Wears slowly and evenly a'ndhas an extremely long useful life requiring practically no attention in molded refractory material in order'to define the fact that the shell is made complete by molding before the contact pieces are secured in place therein. 7 p

I It is'to'be understood that theform' shown lain and integral with the material-o'fthe shell, whereby the shell serves as its own insulator and the race is substantially as wear resisting as themetallic contact mem bers.

In testimonylthat I claim the foregoing,

1 hereto set my hand, this 29th day of October, 1919. p v

CLARENCE H; WALKER. 

